1. Field
The present technology relates to a cylindrical lithium ion secondary battery.
2. Description of the Related Technology
Lithium ion secondary batteries are being widely used in portable electronic devices and power sources of hybrid automobiles or electric vehicles because of various advantages, including a high operation voltage, a high energy density per unit weight, and so forth.
The lithium ion secondary battery can be largely classified as cylinder type secondary battery, a prismatic type secondary battery, a pouch type secondary battery. Specifically, the cylindrical lithium ion secondary battery generally includes a cylindrical electrode assembly, a cylindrical can coupled to the electrode assembly, an electrolyte injected into the can to allow movement of lithium ions, and a cap assembly coupled to one side of the can to prevent leakage of the electrolyte and separation of the electrode assembly.